Genetic Characterization of Toxoplasma gondii Isolates and Toxoplasmosis Seroprevalence in Stray Cats of ?zmir,Turkey

Currently, some Toxoplasma gondii genotypes are being associated with serious clinical presentations. A recent report showing the Africa 1 genotype in two local congenital toxoplasmosis cases acquired in Turkey formed the basis of this study because atypical Africa 1 genotype is most frequently detected in animals and patients from sub-Saharan Africa. Since stray cats are considered as the linkage between wild life and urban life in T. gondii transmission, the present study aimed to isolate and characterize T. gondii strains circulating in stray cats of İzmir (Western Turkey). A secondary objective was to determine toxoplasmosis seroprevalence in this cat population. Tissues obtained from 100 deceased stray cats were bioassayed and isolated strains were genotyped using 15 microsatellite markers. In addition, toxoplasmosis seroprevalence was analyzed in 1121 cat sera collected from several large veterinary clinics in İzmir. Among the 22 isolates, 19 were Type II (86.3%), two were Type III (9%) and one was Africa 1 genotype (4.5%). The overall seropositivity rates in cats were 42–48% and 33.4–34.4% according to IFA and ELISA, respectively. Seroprevalence in deceased cats was significantly higher than in healthy cats (P = 0.0033). Finding both the major clonal Type II lineage together with the Type III lineage also found in Middle East, and an atypical genotype, Africa 1 appears consistent with the specific geographic location of Turkey between three continents and raises the possibility of transportation of these strains between continents through trade routes or long distance migratory birds. In addition, the first large study of toxoplasma seroprevalence in a stray cat population was also reported. The relatively high seropositivity rates and the variety of T. gondii genotypes confirm the local stray cat population as a risk factor for human toxoplasmosis in İzmir.     

The covalent bioconjugate of multiwalled carbon nanotube and amino‐modified linearized plasmid DNA for gene delivery

Carbon nanotubes (CNTs) are allotropes of carbon, which have unique physical, mechanical, and electronic properties. Among various biomedical applications, CNTs also attract interest as nonviral gene delivery systems. Functionalization of CNTs with cationic groups enables delivery of negatively charged DNA into cells. In contrast to this well‐known strategy for DNA delivery, our approach included the covalent attachment of linearized plasmid DNA to carboxylated multiwalled CNTs (MWCNTs). Carboxyl groups were introduced onto MWCNTs by oxidative treatment, and then the carboxyl groups were activated by 1‐ethyl‐3‐(3‐dimethylaminopropyl)carbodiimide (EDC). The whole pQE‐70 vector including the gene encoding green fluorescent protein (GFP) was subjected to polymerase chain reaction (PCR) using the modified nucleotide N6‐(6‐Amino)hexyl‐2′‐deoxyadenosine‐5′‐triphosphate. Hence, free amino groups were introduced onto the linearized plasmid. Covalent bonding between the amino‐modified plasmid DNA and the carboxylated MWCNTs was achieved via EDC chemistry. The resulting bioconjugate was successfully transformed into chemically competent Escherichia coli cells, without necessity of a heat‐shock step at 42°C. The presence of Ca²⁺ in transformation medium was required to neutralize the electrostatic repulsion between DNA and negatively charged outer layer of E. coli. The transformants, which were able to express GFP were inspected manually on ampicillin agar plates. Our study represents a novelty with respect to other noncovalent CNT gene delivery systems. Considering the interest for delivery of linear DNA fragments, our study could give insights into further studies. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 30:224–232, 2014     

Alu insertion polymorphisms and an assessment of the genetic contribution of Central Asia to Anatolia with respect to the Balkans

In the evolutionary history of modern humans, Anatolia acted as a bridge between the Caucasus, the Near East, and Europe. Because of its geographical location, Anatolia was subject to migrations from multiple different regions throughout time. The last, well-known migration was the movement of Turkic speaking, nomadic groups from Central Asia. They invaded Anatolia and then the language of the region was gradually replaced by the Turkic language. In the present study, insertion frequencies of 10 Alu loci (A25 = 0.07, APO = 0.96, TPA25 = 0.44, ACE = 0.37, B65 = 0.57, PV92 = 0.18, FXIIIB = 0.52, D1 = 0.40, HS4.32 = 0.66, and HS4.69 = 0.30) have been determined in the Anatolian population. Together with the data compiled from other databases, the similarity of the Anatolian population to that of the Balkans and Central Asia has been visualized by multidimensional scaling method. Analysis suggested that, genetically, Anatolia is more closely related with the Balkan populations than to the Central Asian populations. Central Asian contribution to Anatolia with respect to the Balkans was quantified with an admixture analysis. Furthermore, the association between the Central Asian contribution and the language replacement episode was examined by comparative analysis of the Central Asian contribution to Anatolia, Azerbaijan (another Turkic speaking country) and their neighbors. In the present study, the Central Asian contribution to Anatolia was estimated as 13%. This was the lowest value among the populations analyzed. This observation may be explained by Anatolia having the lowest migrant/resident ratio at the time of migrations.     

Effect of heteroatom-doped carbon quantum dots on the red emission of metal-conjugated phthalocyanines through hybridization

Quantum dots (QDs) are significant fluorescent materials for energy transfer studies with phthalocyanines (Pcs) and phthalocyanine (Pc)-like biomolecules (such as chlorophylls). Carbon-based QDs, especially, have been used in numerous studies concerning energy transfer with chlorophylls, but the numbers of studies concerning energy transfer between phthalocyanines and carbon-based QDs are limited. In this study, peripherally, hydroxythioethyl terminal group substituted metal-free phthalocyanine (H₂Pc) and zinc phthalocyanine (ZnPc) were noncovalently (electrostatic and/or π–π interaction) attached to carbon QDs containing boron and nitrogen to form QD-Pc nanoconjugates. The QD-Pc conjugates were characterized using different spectroscopic techniques (Fourier transform infrared spectroscopy and transmission electron microscopy). The absorption and fluorescence properties of QD-Pc structures in solution were studied. It was found that the quantum yields of the QDs slightly decreased from 30% to 25% upon doping the QDs with heteroatoms B and N. Förster resonance energy transfer efficiency was calculated as 33% for BCN-QD/ZnPc. For the other conjugates, almost no energy transfer from QDs to Pc cores was observed. It was shown that the energy transfer between QDs to Pc cores was completely different from the energy transfer between QDs and photosynthetic pigments, and therefore we concluded that heteroatom doping in the QD structure and the existence of zinc metal in the phthalocyanine structure is obligatory for an efficient energy transfer.     

Atorvastatin has cardiac safety at intensive cholesterol-reducing protocols for long term, yet its cancer-treatment doses with chemotherapy may cause cardiomyopathy even under coenzyme-Q10 protection

Statins provide strong clinical benefits via reducing stroke deaths, and they are also considered for tumor reduction and chemo-sensitization. High dose atorvastatin in adults (80 mg daily, approx. 1 mg/kg) is proven to afford greater protection against cardiac deaths than does a standard lipid-lowering dose in coronary syndrome. For cancer trials, mega doses up to 30 mg/kg have been used for short term treatments but neither a high nor a mega-dose of atorvastatin has been tested for long term cardiac safety. This may be of special concern, since some animal studies showed deleterious effects of statins on cardiac tissue, which may be related with coenzymeQ (CoQ) depletion. We performed an electron microscopic analysis of rat hearts after low, high-or mega-dose atorvastatin therapy and with or without MNU (methyl-nitrosourea)-stress. MNU + daily high dose atorvastatin treatment for 13 months did not produce severe cardiac toxicity with CoQ. However, at mega doses (30 mg/kg) and with MNU, mitochondrial damage and myofibrillary disintegration was obvious. Strong proliferation of mitochondria under high dose atorvastatin therapy with CoQ may explain the lack of cardiotoxicity; and this finding seems to parallel recent data that statins induce HNF-4 and PPAR-alpha, both responsible for mitochondria-proliferation. Employment of statins for tumor chemo-sensitization at high-dosage and for long term treatments may require strategies to direct the mevalonate-entry differentially into cardiac and tumor cells and to develop a protocol analogous to folic acid salvage of methotrexate toxicity.     

The determination of relationship between “excision repair cross-complementing group 1” (ERCC1) gene T19007C and C8092A single nucleotide polymorphisms and clinicopathological parameters in non-small cell lung cancer

DNA repair plays a key role in prevention of carcinogenesis and one of the most important DNA repair mechanisms is nucleotide excision repair (NER) pathway. This pathway includes a number of genes such as excision repair cross-complementing group 1 (ERCC1) gene which are responsible for the 5′ incision of damaged DNA. A reduced DNA repair capacity associated with ERCC1 mRNA level has been observed in lung carcinogenesis. Two single nucleotide polymorphisms (SNPs) in ERCC1 gene, T19007C (rs11615) and C8092A (rs3212986), reportedly predict to affect the mRNA of ERCC1 in non-small cell lung cancer (NSCLC). To examine the role of two common SNPs in ERCC1 gene further, we conducted this study where 80 cases histopatologically diagnosed as NSCLC were genotyped. Genomic DNA was extracted from formalin-fixed, paraffin embedded tissues and two SNPs were analyzed using real-time PCR. The distributions of TT, TC, and CC genotypes of the T19007C SNP were 40, 44 and 16%, respectively. Significantly increased frequency of the patients carrying at least one 19007C allele was observed in early stage compared to advanced stage (P = 0.002). And also, the frequency of TC and CC genotypes significantly increased in younger patients compared to older patients (P = 0.035). Regarding C8092A SNP, the distribution of CC, CA, and AA genotypes was 38, 51 and 11%, respectively. There was no significant difference in the genotype distribution between C8092A SNP and clinicopathological parameters. This study indicated that harboring at least one 19007C allele may have protective effect in NSCLC.     

Identification of potential serodiagnostic and subunit vaccine antigens by antibody profiling of toxoplasmosis cases in Turkey

Toxoplasmosis, caused by infection of the protozoan parasite Toxoplasma gondii, is associated with mild disease in healthy individuals, whereas individuals with depressed immunity may develop encephalitis, neurologic disorders, and other organ diseases. Women who develop acute toxoplasmosis during pregnancy are at risk of transmitting the infection to the fetus, which may lead to fetal damage. A diagnosis is usually confirmed by measuring IgG, or IgM where it is important to determine the onset of infection. A negative IgM result essentially excludes acute infection, whereas a positive IgM test is largely uninterpretable because IgM can persist for up to 18 months after infection. To identify antigens for improved diagnosis of acute infection, we probed protein microarrays displaying the polypeptide products of 1357 Toxoplasma exons with well-characterized sera from Turkey. The sera were classified according to conventional assays into (1) seronegative individuals with no history of T. gondii infection; (2) acute infections defined by clinical symptoms, high IgM titers, and low avidity IgG; (3) chronic/convalescent cases with high avidity IgG but persisting IgM; (iv) true chronic infections, defined by high avidity IgG and no IgM. We have identified 38 IgG target antigens and 108 IgM target antigens that can discriminate infected patients from healthy controls, one or more of which could form the basis of a 'tier-1' test to determine current or previous exposure. Of these, three IgG antigens and five IgM antigens have the potential to discriminate chronic/IgM persisting or true chronics from recent acutely infected patients (a 'tier-2' test). Our analysis of the antigens revealed several enriched features relative to the whole proteome, which include transmembrane domains, signal peptides, or predicted localization at the outer membrane. This is the first protein microarray survey of the antibody response to T. gondii, and will help in the development of improved serodiagnostics and vaccines.     

Enhanced fluorescence of photosynthetic pigments through conjugation with carbon quantum dots

Photosynthesis Research - Light harvesting in photosynthesis is currently an issue on-debate and studied widely in all over the world. Studies on light harvesting mainly focus on enlightening...     

Altered Resting-State Functional Connectivity of the Frontal-Striatal Reward System in Social Anxiety Disorder

We investigated differences in the intrinsic functional brain organization (functional connectivity) of the human reward system between healthy control participants and patients with social anxiety disorder. Functional connectivity was measured in the resting-state via functional magnetic resonance imaging (fMRI). 53 patients with social anxiety disorder and 33 healthy control participants underwent a 6-minute resting-state fMRI scan. Functional connectivity of the reward system was analyzed by calculating whole-brain temporal correlations with a bilateral nucleus accumbens seed and a ventromedial prefrontal cortex seed. Patients with social anxiety disorder, relative to the control group, had (1) decreased functional connectivity between the nucleus accumbens seed and other regions associated with reward, including ventromedial prefrontal cortex; (2) decreased functional connectivity between the ventromedial prefrontal cortex seed and lateral prefrontal regions, including the anterior and dorsolateral prefrontal cortices; and (3) increased functional connectivity between both the nucleus accumbens seed and the ventromedial prefrontal cortex seed with more posterior brain regions, including anterior cingulate cortex. Social anxiety disorder appears to be associated with widespread differences in the functional connectivity of the reward system, including markedly decreased functional connectivity between reward regions and between reward regions and lateral prefrontal cortices, and markedly increased functional connectivity between reward regions and posterior brain regions.     

Methionine supplementation improves ram sperm parameters during liquid storage at 5 °C

The aim of this study was to investigate the effects of methionine and lipoic acid on ram sperm parameters during liquid storage (5 °C). Ejaculates collected from five Merino rams were pooled at 37 °C. Each pooled ejaculate was divided into five equal aliquots and diluted (37 °C) with five extenders, one of which was without additives, two of which contained methionine at two different doses, and the other two of which contained lipoic acid at two different doses. Sperm parameters were determined at 0, 24, 48, 72 and 96 h of liquid storage at 5 °C.